--- a/src/arrow/util/string_util.h	2026-06-04 20:53:29.410977462 +0200
+++ b/src/arrow/util/string_util.h	2026-06-04 20:53:54.899713942 +0200
@@ -19,6 +19,7 @@
 
 #include <memory>
 #include <ostream>
+#include <sstream>
 #include <string>
 #include <type_traits>
 #include <utility>